The theoretical conformational structure analyses were performed using density functional theory for thiol and thione tautomeric forms of thioacetic acid (TAA). At the B3LYP/6-311++G(d,p) level, thiol [CH3(C-O)SH] and thione [CH3(C=S)OH] were found more stable than anti forms and the energy differences between these two forms were computed to be ca. 6.7 kJ mol-1 and ca. 27 kJ mol-1, respectively. Barrier energies for thiol and thione forms of thioacetic acid were calculated by using the density functional theory [DFT(B3LYP)/6-311++G(d,p)] method contributing to more than 90% of the population in gas phase at room temperature and also reported a theoretical study on vibrational spectra of thiol and thione tautomefic forms of thioacetic acid obtained by the density functional theory.

The structure, conformers, energies and vibrational spectra of the important nipecotamide molecule have been characterized by FT-IR (mid-IR, far-IR), FT-Raman spectroscopy and by DFT calculations. The structure is optimized by B3LYP/6-311++G(d,p) calculations. All vibrational frequencies...

The FT-IR, FT-Raman and FT-NMR spectra of 4-Methyl-2-phenylimidazole (4M2PI)molecule was recorded and analyzed. The tautomeric, structural and spectroscopic analysis of the title molecule was made by using density functional harmonic calculations. For the title molecule, only one tautomeric form...

The vibrational spectra of linear AlC3 and AlC3Al, formed by trapping the products of the dual laser evaporation of aluminum and carbon rods in solid Ar at âˆ¼10 K, were observed. Fourier transform infrared (FTIR) measurements of 13C isotopic shifts are in good agreement with the predictions...

The tautomeric composition of isolated adenine has been analyzed using computational IR spectroscopy. A comparison with experimental data has demonstrated that, in addition to adenine-NH, which dominates in the quantitative content, two more tautomers that have the NH imino and NH amino forms...

The FTIR and FT-Raman spectra of 2-benzoyl thiophene have been recorded in the region 4000-450 cm-1 and 4000-100 cm-1. The molecular structure, geometry optimization, vibrational frequencies and thermodynamic parameters were calculated using density functional B3LYP method with 6-311++G**basis...

A theoretical study of the structure and vibrational spectrum of methyl-Î²-D-glucopyranoside is performed with allowance for the hydrogen bond effect on them. At the density functional theory level with the use of the B3LYP functional in the 6-31G( d) basis set the structural dynamic models of...

IR vibrational spectroscopy has been employed to study liquid-liquid phase transitions of trans-1,2-dichloroethylene (TDCE). The temperature dependence of the vibrational frequency, band absorbance, and band broadening has been analyzed in the temperature range of 293â€“237 K. All peaks...

The IR spectrum and structure of methyl-Î²-D-glucopyranoside have been studied theoretically taking into account the influence on them of the hydrogen bond formed in the sample. Density-functional theory with the B3LYP functional in basis 6-31G( d) was used to minimize the energies and...